The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A073804 Number of divisors of n is greater than that of sigma[n]. 7
 4, 9, 16, 18, 25, 36, 48, 50, 64, 72, 80, 81, 100, 112, 144, 162, 180, 192, 196, 200, 208, 225, 240, 252, 256, 288, 289, 300, 320, 324, 336, 400, 432, 441, 448, 450, 468, 484, 512, 576, 578, 592, 624, 625, 648, 676, 700, 704, 720, 729, 768, 784, 800, 810, 832 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 FORMULA Solutions to A000005(x)>A062068(x)=A000005[A000203(x)] EXAMPLE x=25: D[25]={1,5,25},3 divisors; D[sigma(25)]={1,31},2 divisors; 2<3, so 25 is here. x-48:D[48]={1,2,3,4,6,8,12,16,24,48},10 divisors; D[sigma(48)]={1,2,4,31,62,124},6 divisors, 6<10 so 48 is here. MATHEMATICA Do[s=DivisorSigma[0, DivisorSigma[1, n]]; s0=DivisorSigma[0, n]; If[Greater[s0, s], Print[n]], {n, 1, 1000}] Select[Range[900], DivisorSigma[0, #]>DivisorSigma[0, DivisorSigma[1, #]]&] (* Harvey P. Dale, Jan 18 2017 *) CROSSREFS Cf. A000005, A000203, A062068, A073802, A073803, A037197. Sequence in context: A235993 A102646 A104021 * A219364 A195212 A332443 Adjacent sequences:  A073801 A073802 A073803 * A073805 A073806 A073807 KEYWORD nonn AUTHOR Labos Elemer, Aug 13 2002 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 2 16:06 EDT 2020. Contains 334787 sequences. (Running on oeis4.)